Diesel Additive for cleaning engine

N

nigelstgeorge

Well-Known Member
Joined
13 May 2007
Messages
124
Location
France
www.iledere-france.com
Hi - does anyone have any good recommendation for an additive than can be added to the diesel that cleans the engine and generally de-cokes it. I tend to run my engine a Volvo MD22L at around 2,000 RPM and notice that if I raise that for a short time to 3,000 + revs I get a lot of sooty smoke and rubbish out of the exhaust.

2,000 RPM is my average cruising speed giving me 6.5 - 7 knots and is an economical speed.

regards Nigel
 
nigelstgeorge said:
Hi - does anyone have any good recommendation for an additive than can be added to the diesel that cleans the engine and generally de-cokes it. I tend to run my engine a Volvo MD22L at around 2,000 RPM and notice that if I raise that for a short time to 3,000 + revs I get a lot of sooty smoke and rubbish out of the exhaust.

2,000 RPM is my average cruising speed giving me 6.5 - 7 knots and is an economical speed.

regards Nigel
Click to expand...

i have just used Redex diesel treatment ( Asda £3.60 )for the first time @ 800 hrs. i usd to get a little smoke @ full revs & that is now reduced to virtually nil
 
You need to run these engines hard or they will get sooted up. see this http://www.marineengine.com/boat-forum/showthread.php?t=2719
I had a problem with white smoke at start up I put some injector cleaner in the fuel from Halfords and when i next took the boat out run the engine at max revs (3000rpm) for about ten minutes. This has cleaned up the smoke when starting up and it runs a lot cleaner
Maurice
 
No solvent on earth will dissolve carbon. It is completely inert to anything you or I could buy. Additives for fuel to 'clean up' engines, upper cylinder lubricants, etc are snake oil. Follow the advice of all major engine manufacturers - run it flat out under load for 15 - 30 minutes. The carbon will be oxidised by this treatment and the engine will be restored to its carbon-free state.

Take your boat to a yard with the same complaint. They will do exactly what I recommend and charge you £100 for it.
 
In addition to previous suggestions the exhaust elbow may be partially choked, requiring cleaning by dismantling the exhaust hose and mechanically removing built up carbon etc..

This is unlikely to be effected by fuel additive which at best cleans primarily the injectors.
 
vyv_cox said:
No solvent on earth will dissolve carbon. It is completely inert to anything you or I could buy. Additives for fuel to 'clean up' engines, upper cylinder lubricants, etc are snake oil. Follow the advice of all major engine manufacturers - run it flat out under load for 15 - 30 minutes. The carbon will be oxidised by this treatment and the engine will be restored to its carbon-free state.

Take your boat to a yard with the same complaint. They will do exactly what I recommend and charge you £100 for it.
Click to expand...

Correct! and only £100 - and thats a bargain!!! and lots of boat owners every year fall for it.
 
nigelstgeorge said:
Thanks everyone - looks like running at 2000 RPM ok but should run at 2500-3000 occasionally to clear crud out of the engine
regards
Nigel
Click to expand...

The Yanmar workshop manual suggests running at maximum revs (3600) for 5 minutes after every 2 hours at cruising revs, which in my case is usually either just above or just below 2000 rpm. It's a bit worrying at first to see how much black smoke is emitted, and how much the stern drags down! but it definitely makes a difference to the engine's running afterwards
 
Agree entirely with the above. Forget the snake oil, and give the engine a 10 - 20 minute blast at or near full throttle and it will run much better. Same with diesel cars that are used in heavy city traffic a lot or for stop start work. A blast down the motorway will clear it through and get it running sweet again. The local garage charges £75 for the priviledge of a bash down the M27 and back to get diesels running sweet again.
 
If you look at the material data sheets for most injector cleaners the dominant component is Kerosene..yup..good old Paraffin. Its not a cure, but can help in relatively small amounts, and not in every tankful. But yes, a good old blast at top revs is probably just as good.

SWMBO drives her turbo diesel car so slowly she clogs it up regularly. It needs a few full throttle runs to clear it.

Tim
 
You must log in or register to reply here.

Share this page

Top